68 
BULLETIN 1476, U. S. DEPARTMENT OF AGRICULTURE 
area. In the other areas of the United States where the insect is 
present only a slight infestation in these plants as yet has occurred. 
Table 20 details field counts of infestation in 17 of the more sus- 
ceptible and widely dispersed weeds and wild grasses during 1920 
and 1921 in cultivated fields and waste areas, showing average infes-- 
tation in that portion of the New England area where the European 
Fig. 32/ — Typical injury to bolls of cotton by European corn borer. Cotton grown 
experimentally at Medford, Mass. Photo taken September, 1921 
corn borer has become well established. It does not include small 
isolated patches of weeds which represented the maximum infesta- 
tion. These counts were taken during the growing season at a time 
when the plants had reached full size, and while larvae contained 
in each plant examined apparently were feeding therein. It was 
not possible in every instance, however, to ascertain whether each 
individual was actually feeding or was using the plant as a shelter. 
